1 Sociodemography and exposure

1.1 Sociodemography

Table 1. Socio-demographic characteristics of respondents.
Characteristic	N = 991¹
What sex were you assigned at birth?
Female	557 (56.2%)
Male	434 (43.8%)
Intersex	0 (0%)
(Missing)	0
Which of the following labels best describes your social and felt gender?
Female	550 (56.1%)
Male	427 (43.5%)
Other	4 (0.41%)
(Missing)	10
What is your highest completed education?
None	1 (0.11%)
Incomplete compulsory schooling	1 (0.11%)
Compulsory schooling	22 (2.32%)
One-year transitional program	4 (0.42%)
General education school	16 (1.69%)
Apprenticeship/vocational school	182 (19.2%)
Gymnasial maturity	52 (5.49%)
Professional maturity	18 (1.90%)
Federal diploma exam	101 (10.7%)
Higher vocational school	114 (12.0%)
Bachelor degree	138 (14.6%)
Master degree	215 (22.7%)
Doctorate/habilitation	84 (8.86%)
(Missing)	43
Since when have you been living in Switzerland?
Since birth	740 (74.9%)
Born in Switzerland but also lived abroad	60 (6.07%)
Born abroad	188 (19.0%)
(Missing)	3
What is your marital status?
Married, living with spouse	529 (55.5%)
Married, permanently separated	10 (1.05%)
Registered partnership, living together	3 (0.31%)
Registered partnership, separated	1 (0.10%)
Single, stable partnership	150 (15.7%)
Single, living alone	126 (13.2%)
Divorced	96 (10.1%)
Widowed	38 (3.99%)
(Missing)	38
Occupation according to CH-ISCO 2019
Administrative support staff	186 (31.7%)
Directors, senior executives and managers	3 (0.51%)
Intellectual and scientific professions	59 (10.1%)
Intermediate occupations	230 (39.2%)
Personal services staff, shopkeepers and sales assistants	108 (18.4%)
(Missing)	405
¹ n (%)

1.2 Exposures from inclusion questionnaire

Almost all participants (98.2%) reported having received vaccines at some point, and most indicated full mobility, with 87.1% having no problems walking and fewer than 4% reporting moderate to severe difficulties. A large majority (99.8%) had traveled abroad for more than two days, with Europe being the most frequently visited continent (94%), followed by North America (60.4%), Asia (54.1%), and Africa (46.5%). When asked about future pandemic preparedness, respondents highlighted the importance of combating misinformation (69.7%) and maintaining public awareness (68.2%) and government commitment (55.8%). Other challenges mentioned included strengthening pathogen surveillance (35.4%) and addressing regulatory barriers in vaccine production (28.6%), while climate change mitigation (18.2%) and ventilation improvements (12.8%) were less commonly emphasized.

Table 2. Exposures from inclusion questionnaire.
Characteristic	N = 991¹
Have you ever received any vaccines?
Yes	960 (98.2%)
No	18 (1.84%)
(Missing)	13
Please select what best describes your mobility today
I have no problems walking around	844 (87.1%)
I have slight problems walking around	89 (9.18%)
I have moderate problems walking around	28 (2.89%)
I have severe problems walking around	8 (0.83%)
I am unable to walk around	0 (0%)
(Missing)	22
Have you ever stayed abroad for more than two days?
Yes	955 (99.8%)
No	2 (0.21%)
(Missing)	34
On which continent?
Europe	932 (94.0%)
North America	599 (60.4%)
Central America	184 (18.6%)
South America	243 (24.5%)
Africa	461 (46.5%)
Asia	536 (54.1%)
Oceania	215 (21.7%)
(Missing)	0
Thinking about the next pandemic, what do you see as the main challenges for preparedness?
Maintaining public awareness of a possible pandemic	676 (68.2%)
Maintaining government commitment to pandemic preparedness	553 (55.8%)
Mitigating the effects of climate change	180 (18.2%)
Regulatory barriers to scaling up vaccine production in low- and middle-income countries	283 (28.6%)
Strengthening surveillance to identify potential pandemic pathogens	351 (35.4%)
Combating misinformation about pandemic threats	691 (69.7%)
Installing adequate ventilation in workplaces and homes	127 (12.8%)
(Missing)	0
¹ n (%)

The EQ VAS records the patient’s self-rated health on a vertical visual analogue scale where the endpoints are labelled ‘The best health you can imagine’ and ‘The worst health you can imagine’. The VAS can be used as a quantitative measure of health outcome that reflects the patient’s own judgement. We observe an average of 83 (SD 12.8), consistent with a representative survey in French-speaking Switzerland reporting a mean EQ-VAS of 81.7 (SD 15.5). (cite https://doi.org/10.1111/j.1524-4733.2010.00727.x)

1.3 Municipality of residence

For each municipality in the canton of Bern, we mapped the number of survey respondents. The map illustrates the geographic distribution of the surveyed population, with a markedly higher concentration of respondents in the city of Bern than in the rest of the canton.

2 General knowledge

2.1 Baseline control variables

Table 3. Understanding check up.
Introductory text	N = 991¹
Please read the following text carefully before answering the questions: A vector is an organism that can transmit a pathogen (virus, bacterium, or parasite), primarily by feeding on an infected host (human or animal), and then transmitting it to other hosts. Tick-borne encephalitis is a disease transmitted by tick bites. Would you classify it as a vector-borne disease?
Yes	753 (78.4%)
No	106 (11.0%)
I don't know	102 (10.6%)
(Missing)	30
¹ n (%)

Table 4. Preliminary knowledge check-up.
Question	N = 991¹
Have you heard of the following diseases?
West Nile fever	290 (29.3%)
Dengue	876 (88.4%)
Zika	616 (62.2%)
Chikungunya	195 (19.7%)
Lyme disease	751 (75.8%)
Influenza	929 (93.7%)
Measles	945 (95.4%)
None of these	2 (0.20%)
(Missing)	0
Have you heard of the following organisms?
Ticks	951 (96.0%)
Mosquitoes	949 (95.8%)
Wasps	920 (92.8%)
Bed bugs	911 (91.9%)
None of these	1 (0.10%)
(Missing)	0
¹ n (%)

A majority of participants answered consistently when linking vectors to disease transmission, but a minority displayed contradictions. About 6% denied ticks or mosquitoes as transmitters while simultaneously identifying them as responsible for disease transmission. In total, 10.7% of respondents contradicted themselves in at least one case. This suggests that while knowledge was generally coherent, a small but notable share of respondents held conflicting beliefs or had difficulties applying knowledge consistently.

Table 5. Logical contradictions in respondents’ answers.
Question	N = 991¹
Denied tick as transmitter and identified ticks as transmiting a disease
Consistent	902 (94.1%)
Contradiction	57 (5.94%)
(Missing)	32
Denied mosquitoes transmitter and identified mosquitoes as transmiting a disease
Consistent	896 (94.0%)
Contradiction	57 (5.98%)
(Missing)	38
Any of the two contradiction
Consistent	850 (89.3%)
Contradiction	102 (10.7%)
(Missing)	39
¹ n (%)

2.2 Item-level accuracy

Table 6. Vector-borne disease test item.
Test item	N = 709¹
Question : Which of these diseases do you think are vector-borne diseases?
(Missing)	0
West Nile correctly classified as VBD
Incorrect	421 (59.4%)
Correct	288 (40.6%)
Dengue correctly classified as VBD
Incorrect	98 (13.8%)
Correct	611 (86.2%)
Zika correctly classified as VBD
Incorrect	222 (31.3%)
Correct	487 (68.7%)
Chikungunya correctly classified as VBD
Incorrect	480 (67.7%)
Correct	229 (32.3%)
Lyme correctly classified as VBD
Incorrect	121 (17.1%)
Correct	588 (82.9%)
Influenza correctly classified as not a VBD
Incorrect	142 (20.0%)
Correct	567 (80.0%)
Measles correctly classified as not a VBD
Incorrect	123 (17.3%)
Correct	586 (82.7%)
¹ n (%)

Table 7. Vector test item.
Test item	N = 709¹
Question : Which of these organisms transmit diseases to humans?
(Missing)	0
Ticks correctly identified as transmitting disease
Incorrect	0 (0%)
Correct	709 (100.0%)
Mosquitoes correctly identified as transmitting disease
Incorrect	9 (1.27%)
Correct	700 (98.7%)
Wasps correctly identified as not transmitting disease
Incorrect	46 (6.49%)
Correct	663 (93.5%)
Bed bugs identified as not transmitting disease
Incorrect	163 (23.0%)
Correct	546 (77.0%)
¹ n (%)

Table 8. Disease–vector matching test item.
Test item	N = 709¹
Question : Match each disease on the left with its vector on the right (one per row). E.g. ’tick-borne encephalitis’ -> ’ticks’.
TBE correctly matched to ticks
Incorrect	3 (0.42%)
Correct	704 (99.6%)
West Nile correctly matched to mosquitoes
Incorrect	278 (43.4%)
Correct	363 (56.6%)
Dengue correctly matched to mosquitoes
Incorrect	77 (11.1%)
Correct	616 (88.9%)
Zika correctly matched to mosquitoes
Incorrect	184 (27.7%)
Correct	480 (72.3%)
Chikungunya correctly matched to mosquitoes
Incorrect	361 (58.2%)
Correct	259 (41.8%)
Lyme correctly matched to ticks
Incorrect	87 (12.4%)
Correct	613 (87.6%)
Influenza correctly matched to none
Incorrect	42 (6.62%)
Correct	592 (93.4%)
Measles correctly matched to none
Incorrect	48 (7.61%)
Correct	583 (92.4%)
¹ n (%)

2.3 Overall knowledge score

We hereby display a more detailed visualization of the repartition of the overall knowledge score by highlighting the relative contribution of knowledge test items (recognizing organisms as vectors, recognizing diseases as VBDs, matching diseases with their corresponding vector) or associated vectors (Wasp/bed bugs distractors, Ticks, Mosquitoes). The ability to identify vector-borne diseases and knowledge about mosquitoes and mosquito-borne diseases appear as important drivers of the overall knowledge score.

3 Individual exposure : open-ended answers

Most respondents reported vaccination against tick-borne encephalitis (FSME/TBE) as their main preventive measure, often mentioning it explicitly for themselves or their children. A smaller number referred to protecting pets (e.g., with tick collars or treatments) as an indirect preventive strategy. Few participants mentioned other measures such as avoiding tall grass or forests, wearing protective clothing or hats, using repellents (sprays, oils, patches), or employing unconventional approaches such as vinegar, vitamin B, or ceramic bracelets. Overall, vaccination was by far the most commonly cited individual preventive action, with other measures appearing rarely and in isolated cases.

Respondents described a wide range of individual strategies to prevent mosquito bites. Common measures included the use of repellents such as insect sprays, mosquito-repellent candles, incense sticks, essential oils (e.g., lavender, clove, oregano), and specialized diffusers or bracelets. Several participants reported installing or using physical barriers such as mosquito nets, insect screens, or curtains, and others emphasized behavioral measures, including keeping lights off in the evening, ventilating rooms during the day, and avoiding open windows at night. Some mentioned directly eliminating mosquitoes indoors through catching, swatting, or using electric devices. Additional approaches included reducing breeding sites by covering or regularly changing standing water, maintaining bat-friendly gardens, or applying larvicides. A few respondents also referred to vaccination or the use of vitamin supplements as protective measures.

Knowledge, Attitudes and Practices on Vector-Borne Diseases in Switzerland – 2025

Supplement

Lilian Goepp, Nina Huber, Arlette Szelecsenyi, Julien Riou

2025-09-03